Cytoskeleton最新文献

{"title":"Growth-induced collective bending and kinetic trapping of cytoskeletal filaments","authors":"Deb Sankar Banerjee,&nbsp;Simon L. Freedman,&nbsp;Michael P. Murrell,&nbsp;Shiladitya Banerjee","doi":"10.1002/cm.21877","DOIUrl":"10.1002/cm.21877","url":null,"abstract":"<p>Growth and turnover of actin filaments play a crucial role in the construction and maintenance of actin networks within cells. Actin filament growth occurs within limited space and finite subunit resources in the actin cortex. To understand how filament growth shapes the emergent architecture of actin networks, we developed a minimal agent-based model coupling filament mechanics and growth in a limiting subunit pool. We find that rapid filament growth induces kinetic trapping of highly bent actin filaments. Such collective bending patterns are long-lived, organized around nematic defects, and arise from competition between filament polymerization and bending elasticity. The stability of nematic defects and the extent of kinetic trapping are amplified by an increase in the abundance of the actin pool and by crosslinking the network. These findings suggest that kinetic trapping is a robust consequence of growth in crowded environments, providing a route to program shape memory in actin networks.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 8","pages":"409-419"},"PeriodicalIF":2.4,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21877","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141075705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TNF-alpha promotes cilia elongation via mixed lineage kinases signaling in mouse fibroblasts and human RPE-1 cells","authors":"Amrita Kumari,&nbsp;Amada D. Caliz,&nbsp;Hyung-Jin Yoo,&nbsp;Shashi Kant,&nbsp;Anastassiia Vertii","doi":"10.1002/cm.21873","DOIUrl":"10.1002/cm.21873","url":null,"abstract":"<p>The primary cilium is a characteristic feature of most non-immune cells and functions as an environmental signal transduction sensor. The defects in primary cilium have profound effects on the developmental program, including the maturation of retinal epithelium. The ciliary length is tightly regulated during ciliogenesis, but the impact of inflammation on ciliary length remains elusive. The current study investigates the outcome of inflammatory stimuli for the primary cilium length in retinal epithelium cells and mouse embryonic fibroblasts. Here, we report that exposure to the pro-inflammatory cytokine TNF-alpha elongates cilia in a mixed-lineage kinase (MLK)-dependent manner. Pro-inflammatory stimuli such as bacterial LPS and interferon-gamma have similar effects on ciliary length. In contrast, febrile condition-mimicking heat stress dramatically reduced the number of ciliated cells regardless of TNF-alpha exposure but did not shorten TNF-induced elongation, suggesting distinct but rapid effects of inflammatory stresses on ciliogenesis.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 11","pages":"639-647"},"PeriodicalIF":2.4,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141066212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The unique properties of Big tau in the visual system","authors":"Itzhak Fischer,&nbsp;Theresa Connors,&nbsp;Julien Bouyer,&nbsp;Ying Jin","doi":"10.1002/cm.21875","DOIUrl":"10.1002/cm.21875","url":null,"abstract":"<p>Tau is a microtubule associated protein that plays important roles in regulating the properties of microtubules and axonal transport, as well as tauopathies associated with toxic aggregates leading to neurodegenerative diseases. It is encoded by the MAPT gene forming multiple isoforms (45–60 kDa) by alternative splicing which are developmentally regulated. The high molecular weight (MW) tau isoform of 105 kDa, termed Big tau, was originally discovered in the peripheral nervous system (PNS) but later found in selective CNS areas. It contains an additional large exon 4a generating a long projecting domain of about 250 amino acids. Here we investigated the properties of Big tau in the visual system of rats, its distribution in retinal ganglion cells and the optic nerve as well as its developmental regulation using biochemical, molecular and histological analyses. We discovered that Big tau is expresses as a 95 kDa protein (termed middle MW) containing exons 4a, 6 as well as exon 10 which defines a 4 microtubule-binding repeats (4R). It lacks exons 2/3 but shares the extensive phosphorylation characteristic of other tau isoforms. Importantly, early in development the visual system expresses only the low MW isoform (3R) switching to both the low and middle MW isoforms (4R) in adult retinal ganglion neurons and their corresponding axons. This is a unique structure and expression pattern of Big tau, which we hypothesize is associated with the specific properties of the visual system different from what has been previously described in the PNS and other areas of the nervous system.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 9-10","pages":"488-499"},"PeriodicalIF":2.4,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140960163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Author profile—Prashali Chauhan","authors":"Prashali Chauhan","doi":"10.1002/cm.21874","DOIUrl":"10.1002/cm.21874","url":null,"abstract":"","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 8","pages":"420-421"},"PeriodicalIF":2.4,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140960068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrastructure expansion microscopy (U-ExM) of mouse and human kidneys for analysis of subcellular structures","authors":"Ewa Langner,&nbsp;Pongpratch Puapatanakul,&nbsp;Rachel Pudlowski,&nbsp;Dema Yaseen Alsabbagh,&nbsp;Jeffrey H. Miner,&nbsp;Amjad Horani,&nbsp;Susan K. Dutcher,&nbsp;Steven L. Brody,&nbsp;Jennifer T. Wang,&nbsp;Hani Y. Suleiman,&nbsp;Moe R. Mahjoub","doi":"10.1002/cm.21870","DOIUrl":"10.1002/cm.21870","url":null,"abstract":"<p>Ultrastructure expansion microscopy (U-ExM) involves the physical magnification of specimens embedded in hydrogels, which allows for super-resolution imaging of subcellular structures using a conventional diffraction-limited microscope. Methods for expansion microscopy exist for several organisms, organs, and cell types, and used to analyze cellular organelles and substructures in nanoscale resolution. Here, we describe a simple step-by-step U-ExM protocol for the expansion, immunostaining, imaging, and analysis of cytoskeletal and organellar structures in kidney tissue. We detail the critical modified steps to optimize isotropic kidney tissue expansion, and preservation of the renal cell structures of interest. We demonstrate the utility of the approach using several markers of renal cell types, centrioles, cilia, the extracellular matrix, and other cytoskeletal elements. Finally, we show that the approach works well on mouse and human kidney samples that were preserved using different fixation and embedding conditions. Overall, this protocol provides a simple and cost-effective approach to analyze both preclinical and clinical renal samples in high detail, using conventional lab supplies and standard widefield or confocal microscopy.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 11","pages":"618-638"},"PeriodicalIF":2.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140878074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myosin phosphatase targeting subunit1 controls localization and motility of Rab7‐containing vesicles: Is myosin phosphatase a cytoplasmic dynein regulator?","authors":"Fumio Matsumura, Takashi Murayama, Ryoko Kuriyama, Aya Matsumura, Shigeko Yamashiro","doi":"10.1002/cm.21871","DOIUrl":"https://doi.org/10.1002/cm.21871","url":null,"abstract":"Myosin phosphatase targeting subunit1 (MYPT1) is a critical subunit of myosin phosphatase (MP), which brings PP1Cδ phosphatase and its substrate together. We previously showed that MYPT1 depletion resulted in oblique chromatid segregation. Therefore, we hypothesized that MYPT1 may control microtubule‐dependent motor activity. Dynein, a minus‐end microtubule motor, is known to be involved in mitotic spindle assembly. We thus examined whether MYPT1 and dynein may interact. Proximity ligation assay and co‐immunoprecipitation revealed that MYPT1 and dynein intermediate chain (DIC) were associated. We found that DIC phosphorylation is increased in MYPT1‐depleted cells in vivo, and that MP was able to dephosphorylate DIC in vitro. MYPT1 depletion also altered the localization and motility of Rab7‐containing vesicles. MYPT1‐depletion dispersed the perinuclear Rab7 localization to the peripheral in interphase cells. The dispersed Rab7 localization was rescued by microinjection of a constitutively active, truncated MYPT1 mutant, supporting that MP is responsible for the altered Rab7 localization. Analyses of Rab7 vesicle trafficking also revealed that minus‐end transport was reduced in MYPT1‐depleted cells. These results suggest an unexpected role of MP: MP controls dynein activity in both mitotic and interphase cells, possibly by dephosphorylating dynein subunits including DIC.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"28 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contributions of the individual domains of αIIbβ3 integrin to its extension: Insights from multiscale modeling","authors":"Onkar Joshi,&nbsp;Tomasz Skóra,&nbsp;Anna Yarema,&nbsp;Richard D. Rabbitt,&nbsp;Tamara C. Bidone","doi":"10.1002/cm.21865","DOIUrl":"10.1002/cm.21865","url":null,"abstract":"<p>The platelet integrin α_IIbβ₃ undergoes long-range conformational transitions between bent and extended conformations to regulate platelet aggregation during hemostasis and thrombosis. However, how exactly α_IIbβ₃ transitions between conformations remains largely elusive. Here, we studied how transitions across bent and extended-closed conformations of α_IIbβ₃ integrin are regulated by effective interactions between its functional domains. We first carried out μs-long equilibrium molecular dynamics (MD) simulations of full-length α_IIbβ₃ integrins in bent and intermediate conformations, the latter characterized by an extended headpiece and closed legs. Then, we built heterogeneous elastic network models, perturbed inter-domain interactions, and evaluated their relative contributions to the energy barriers between conformations. Results showed that integrin extension emerges from: (i) changes in interfaces between functional domains; (ii) allosteric coupling of the head and upper leg domains with flexible lower leg domains. Collectively, these results provide new insights into integrin conformational activation based on short- and long-range interactions between its functional domains and highlight the importance of the lower legs in the regulation of integrin allostery.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 8","pages":"393-408"},"PeriodicalIF":2.4,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21865","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure-based modeling of primary cilia mechanics","authors":"Nima Mostafazadeh,&nbsp;Andrew Resnick,&nbsp;Y.-N. Young,&nbsp;Zhangli Peng","doi":"10.1002/cm.21860","DOIUrl":"10.1002/cm.21860","url":null,"abstract":"<p>A primary cilium, made of nine microtubule doublets enclosed in a cilium membrane, is a mechanosensing organelle that bends under an external mechanical load and sends an intracellular signal through transmembrane proteins activated by cilium bending. The nine microtubule doublets are the main load-bearing structural component, while the transmembrane proteins on the cilium membrane are the main sensing component. No distinction was made between these two components in all existing models, where the stress calculated from the structural component (nine microtubule doublets) was used to explain the sensing location, which may be totally misleading. For the first time, we developed a microstructure-based primary cilium model by considering these two components separately. First, we refined the analytical solution of bending an orthotropic cylindrical shell for individual microtubule, and obtained excellent agreement between finite element simulations and the theoretical predictions of a microtubule bending as a validation of the structural component in the model. Second, by integrating the cilium membrane with nine microtubule doublets and simulating the tip-anchored optical tweezer experiment on our computational model, we found that the microtubule doublets may twist significantly as the whole cilium bends. Third, besides being cilium-length-dependent, we found the mechanical properties of the cilium are also highly deformation-dependent. More important, we found that the cilium membrane near the base is not under pure in-plane tension or compression as previously thought, but has significant local bending stress. This challenges the traditional model of cilium mechanosensing, indicating that transmembrane proteins may be activated more by membrane curvature than membrane stretching. Finally, we incorporated imaging data of primary cilia into our microstructure-based cilium model, and found that comparing to the ideal model with uniform microtubule length, the imaging-informed model shows the nine microtubule doublets interact more evenly with the cilium membrane, and their contact locations can cause even higher bending curvature in the cilium membrane than near the base.</p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 8","pages":"369-381"},"PeriodicalIF":2.4,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21860","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Front Cover Image","authors":"","doi":"10.1002/cm.21866","DOIUrl":"https://doi.org/10.1002/cm.21866","url":null,"abstract":"<p>ON THE FRONT COVER: Tissue level cytoskeletal architecture of the inner medullary region of a mouse kidney. Green: Phalloidin fluorescence of F-actin filaments along cell membranes of the renal thin loops and collecting ducts. Red: CD34 immunofluorescence of capillaries. Blue: DAPI fluorescence of the cell nuclei.</p><p>Credit: Girishkumar K. Kumaran (Ariel University, Israel; University of Oxford, UK) &amp; Israel Hanukoglu (Ariel University, Israel)\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 4-5","pages":"C1"},"PeriodicalIF":2.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21866","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140643472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inner Front Cover Image","authors":"","doi":"10.1002/cm.21867","DOIUrl":"https://doi.org/10.1002/cm.21867","url":null,"abstract":"<p>ON THE INNER FRONT COVER: Hs27 fibroblasts stained for Vinculin (green) and F-actin/phalloidin (red) on etched grooved quartz, illustrating the concept of a focal adhesion confinement mechanism in contact guidance at shallow groove depths.</p><p>Credit: Jinny L. Liu &amp; Michael C. Robitaille (U.S. Naval Research Laboratory, USA)\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 4-5","pages":"C2"},"PeriodicalIF":2.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21867","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140643474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}